I have been playing with ES6 for a while and I noticed that while variables declared with var are hoisted as expected...  console.log(typeof name); // undefined var name = "John";   ...variables declared with let or const seem to have some...
I've heard that accessing let and const values before they are initialized can cause a ReferenceError because of something called the temporal dead zone.  What is the temporal dead zone, how does it relate to scope and hoisting, and in what sit...
I've recently come across the const keyword in JavaScript. From what I can tell, it is used to create immutable variables, and I've tested to ensure that it cannot be redefined (in Node.js):  const x = 'const'; const x = 'not-co...
There's the const definition in Exploring ES6 by Dr. Axel Rauschmayer:     const works like let, but the variable you declare must be   immediately initialized, with a value that can’t be changed   afterwards. […]  const bar = 123; bar = 45...
I am interested if there are any limits to what types of values can be set using const in JavaScript—in particular functions. Is this valid? Granted it does work, but is it considered bad practice for any reason?  const doSomething = () => {...
Given that a variable declared with const cannot be reassigned or deleted see    Are there constants in JavaScript? JavaScript const Keyword Is it possible to delete a variable declared using const??   why is it possible to reassign a value to a vari...
Regardless of functional differences, does using the new keywords 'let' and 'const' have any generalized or specific impact on performance relative to 'var'?  After running the program:  function timeit(f, N, S) {     var star...
I always thought that const variables in JavaScript would be constants... like "variables that cannot change". So I always assumed the benefit of using const over let/var would be something like decreased resources usage. But after a quick te...
First, I had asked is it possible: How to create Javascript constants as properties of objects using const keyword?  Now, I gotta ask: why?  The answer to me seems to be 'just because', but it would be so useful to do something like this:  va...
I know that ES6 is not standardized yet, but a lot of browsers currently support const keyword in JS.  In spec, it is written that:     The value of a constant cannot change through re-assignment, and a   constant cannot be re-declared. Because of th...

Tags

Recent Questions

Top Questions

Home Tags Terms of Service Privacy Policy DMCA Contact Us

©2020 All rights reserved.